The Bitcoin transaction lock time is the time at which a particular transaction can be added to the blockchain . This is the earliest time that miners can include the transaction in their hashing of the
Merkle root to attach it in the latest block to the blockchain.
Some research on google 'ld help you.
P.S. Guilelessly, this was an anamolous question from a hero rank member.
Nice (Guilelessly)copy paste from here (anamolous) :
https://www.cryptocompare.com/coins/guides/what-is-bitcoin-transaction-locktime/
http://www.investopedia.com/terms/b/block-bitcoin-block.asp
https://i.imgur.com/PAAf5AE.png
https://i.imgur.com/H1fWXyz.png
I was looking for some more detailed explanation but never mind.